There are many types of portable electrical and electronic devices in use today that include rechargeable batteries, so that device can be used without a cord connecting it to a wall socket connected to a power line or grid. Examples of such cordless electrical devices include power hand tools, bathroom appliances such as electric toothbrushes and shavers, and kitchen appliances such as mixers or electric knives. Examples of portable electronic devices include cellular telephones, pagers, two-way radios, telemetry equipment, personal data assistants (PDA), computers, hand held video games, and audio entertainment devices such as portable radios, compact disc (CD) players, and tape recorders. Normally the batteries in these electrical and electronic devices are re-charged by connecting the device through a cord directly to a power line, or by placing the device in a charger connected by a cord to a power line receiving electrical power from a municipal utility grid or a generator.
There are circumstances, however, under which it is impossible or undesirable to connect to a utility grid through a power cord, or where it is preferable to use another source of power for re-charging the battery. One such circumstance is encountered in operating devices with re-chargeable batteries in a remote outdoor location, perhaps outdoors while back-packing, canoeing, camping, or skiing, where there is no access to utility power lines or portable generators. Carrying extra disposable batteries in such circumstances is not desirable due to extra bulk and weight that must be carried both in and out of the wilderness, so that the spent batteries can be responsibly disposed of in an environmentally friendly manner.
It is also sometimes preferable for safety reasons to avoid the need for connecting a charger to a wall socket, in a kitchen or a bathroom for example, to preclude the risk of inadvertent electrical shock.
In other instances, while it may be possible to run an electrical cord to a charger, it is inconvenient to do so. For example, it is common practice in busy restaurants to give paging devices that vibrate and light up to patrons waiting for tables. These pagers must be kept charged, and it may not be convenient to have an electrical outlet adjacent the maitre d' station, or to run an electrical cord to a remote outlet, for charging the pagers.
What is needed, therefore, is an improved apparatus and method for recharging batteries in portable electrical and electronic devices, in a manner that does not require the device or a charger to be connected to a power line or a generator.